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Biomedical subjects

J Liang

Publications and source records attributed to J Liang.

At least 199 records · Page 11Linked to original sources
PubMed1997

Electrical stimulation of acupuncture points enhances gastric myoelectrical activity in humans.

OBJECTIVE: Acupuncture is known to enhance gastric motility. Electrical acustimulation has been shown to reduce gastric tachyarrhymia in vection-induced motion sickness. The aim of this study was to investigate the effect of electrical stimulation of acupuncture points on gastric myoelectrical activity in healthy humans. METHODS: Nine healthy native Chinese were studied. Gastric myoelectrical activity was recorded using surface electrogastrography (EGG). The EGG recording was made in the fasting state, in a study period during which acupuncture points were electrically stimulated continuously, and in a recovery period after stimulation. The percentage of regular slow waves was assessed by computing the percentage of 2 to 4 cycles per minute slow waves in the EGG. RESULTS: Electrical stimulation significantly increased the percentage of regular slow waves, which was sustained in the recovery period. The increase of the regular slow wave activity resulted from the normalization of arrhythmia. CONCLUSION: Electrical stimulation of acupuncture points may enhance the regularity of gastric myoelectrical activity and may be an option for treatment of gastric dysrhythmia.

Acupuncture Points↗
PubMed1997

[Study of dermatomycosis and survey of pathogens in troops of Hainan area].

Subtropical area is the prevalent area of dermatomycosis with natural conditions suptable for the growth and proliferation of fungi causing suterficial dermatomycosis. Dermatomycosis not only brings about certain sufferings to the military personnel in peacetime, but also causes nonbattle loss in manpower in war time. In the present work, a survey of dermatomycosis in Hainan subtropical area of China and isolation of the pathogens were carried out. The results were as follows: The morbidity of superficial dermatomycosis was 34.1% and it was manifested clinically as tinea pedis, tinea versicolor, tinea corporis, tinea axillaris, tinea cruris, etc.; The main pathogen causing dermatomycosis in this area was Trichophyton rubrum which accounted for 50.4% of the pathogens isolated and the next was Trichophyton gypseum which accounted for 20.3%; Trichophyton rubrum could cause dermatomycosis of many sites of the body in this area, but the main lesious were tinea corporis and tinea cruris.

Adult↗
PubMed1996

Reduced expression of transforming growth factor beta type I receptor contributes to the malignancy of human colon carcinoma cells.

Transforming growth factor beta (TGFbeta) type I (RI) and type II (RII) receptors are essential for TGFbeta signal transduction. A human colon carcinoma cell line, designated GEO, is marginally responsive to TGFbeta and expresses a low level of RI mRNA relative to colon carcinoma cells, which are highly responsive to TGFbeta. Hence, the role of RI as a limiting factor for TGFbeta sensitivity and the contribution of low RI levels to the malignant phenotype of GEO cells were examined. Stable transfection of a tetracycline-regulatable rat RI cDNA increased TGFbeta1 binding to RI and resulted in increased growth inhibition by exogenous TGFbeta1. In contrast, although stable transfection of an RII expression vector into the same GEO cells increased TGFbeta1 binding to RII, growth inhibition by exogenous TGFbeta1 was not altered. This indicated that the low level of RI is a limiting factor for the growth-inhibitory effects of TGFbeta in GEO cells. RI-transfected cells were growth-arrested at a lower saturation density than GEO control cells. They also showed reduced growth and clonogenicity in plating efficiency and soft agarose assays, whereas RII-transfected cells did not show any differences from the NEO control cells in these assays. Tetracycline repressed RI expression in transfected cells and reversed the reduction in plating efficiency of RI-transfected clones, confirming that growth effects were due to increased RI expression in transfected cells. TGFbeta1 neutralizing antibody stimulated the proliferation of RI-transfected cells but had little effect on GEO control cells, indicating that increased autocrine-negative TGFbeta activity also resulted from increased RI expression. Tumorigenicity in athymic nude mice was significantly delayed in RI-transfected cells. These results indicate that low RI expression can be a limiting factor for response to exogenous TGFbeta, as well as TGFbeta autocrine-negative activity, and that reduction of RI expression can contribute to malignant progression.

Activin Receptors, Type I↗
PubMed1996

Crystal structure of P13K SH3 domain at 20 angstroms resolution.

The P13K SH3 domain, residues 1 to 85 of the P1-3 kinase p85 subunit, has been characterized by X-ray diffraction. Crystals belonging to space group P4(3)2(1)2 diffract to 2.0 angstroms resolution and the structure was phased by single isomorphous replacement and anomalous scattering (SIRAS). As expected, the domain is a compact beta barrel with an over-all confirmation very similar to the independently determined NMR structures. The X-ray structure illuminates a discrepancy between the two NMR structures on the conformation of the loop region unique to P13K SH3. Furthermore, the ligand binding pockets of P13K SH3 domain are occupied by amino acid residues from symmetry-related P13K SH3 molecules: the C-terminal residues I(82) SPP of one and R18 of another. The interaction modes clearly resemble those observed for the P13K SH3 domain complexed with the synthetic peptide RLP1, a class 1 ligand, although there are significant differences. The solid-state interactions suggest a model of protein-protein aggregation that could be mediated by SH3 domains.

Amino Acid Sequence↗
PubMed1996

Crystallization and preliminary X-ray analysis of twinned crystals of a chimeric FK506 binding protein 12 and 13 complexed with FK506.

An FKBPI2/13 chimera with the 80s loop of FKBPI3 replacing the corresponding loop in FKBPI2 tightly binds the immunosuppressive agents FK506 and rapamycin and efficiently catalyzes peptidyl-prolyl cis-trans isomerization. However, the chimera's complex with FK506 does not inhibit calcineurin's phosphatase activity [Yang, Rosen & Schreiber (1993). J. Am. Chem. Soc. 115(2), 819-820]. The chimeric protein crystallizes in space group P1 and the crystals are always twinned. The twin composites are related by a twofold twinning axis parallel to the a axis. A resolution data set (1.5 A resolution) for a twinned crystal was collected at CHESS using 0.91 A X-rays and image plates. Preliminary molecular replacement using data between 15 and 3 A and the FKBPI2-FK506 crystal structure as the search model led to a clear solution with a residual of 34.2%. This 3 A resolution structure provides insight into the structural basis of twinning.

Journal Article↗
PubMed1996

Images of cone photoreceptors in the living human eye.

Though the photoreceptor mosaic has been imaged through the intact optics of the eyes of several species, it has not been clear whether individual photoreceptors can be resolved in the living human eye. We have constructed a high-resolution fundus camera and have resolved cones with a spacing as small as 3.5 microns in single images of the fundus. The high contrast of these images implies that almost all the light returning from the retina at this wavelength (555 nm) has passed through the apertures of foveal cones. The average power spectra of our retinal images show that it is possible to recover spatial frequencies as high as 150 c/deg in eyes with normal optical quality, a conclusion that was confirmed with estimates of the optical quality of these eyes obtained with a Hartmann-Shack wavefront sensor. These results emphasize the superiority of the eye's optics over the spatial sampling limits of the retina when the eye's optical quality is optimized. They also show that it would be possible to routinely resolve retinal structures as small as photoreceptors in the normal living eye if its aberrations could be corrected.

Adult↗
PubMed1996

Transitions in cognitive status among the aged in Japan.

This study examines the competing risk of cognitive impairment, mortality and study attrition over a three year period within a national probability sample of Japanese elderly (n = 1506). Younger age and fewer chronic conditions were related to recovery, while older age, being married, poorer self-rated health and depression were related to mortality. Impaired, urban respondents were more likely to drop out of the study than impaired rural respondents. For those 'intact' at baseline, the probabilities of impairment, death and non-response were 7, 6 and 16%. Older, less educated individuals were more likely to become impaired; older males, less educated, married, those in poorer self-rated health with poor functional health were more likely to die; and younger, single, urban living individuals with poor self-rated and functional health, a past smoking history and high levels of depression were the most likely to drop out of the study. A Japanese elder aged 65 is expected to spend about 14.6 years (81%) free from cognitive impairement and about 3.45 years (19%) experiencing some degree of cognitive impairment throughout the remaining lifetime.

Aged↗
PubMed1996

Iron repressible outer membrane proteins of Moraxella bovis and demonstration of siderophore-like activity.

Moraxella bovis (strain Epp 63), grown in RPMI 1640 medium supplemented with desferrioxamine mesylate (0.05 mg/ml) resulted in cell free culture supernatants with an increased chromeazurol-S response indicating the presence of high affinity iron binding ligand(s). Supernatants of cultures where growth occurred in tryptic soy broth, RPMI 1640, or RPMI 1640-desferrioxamine supplemented with ferrous sulfate (10 micrograms/ml) were negative on the chromeazurol-S test. Growth of M. bovis in RPMI 1640 or RPMI 1640-desferrioxamine medium induced the expression of previously unrecognized outer membrane proteins whose expression was repressed when the medium was supplemented with iron and which were not produced when growth occurred in tryptic soy broth.

Bacterial Outer Membrane Proteins↗
PubMed1996

Effect of inflation on interstitial cuff and pressure in liquid-filled rabbit lung.

Degassed rabbit lungs were inflated to 15 cmH2O pressure with 3% albumin solution. To study cuff growth, lungs were frozen in liquid N2 at several (20-120 min) inflation times. Cuff-to-vessel area ratio measured from frozen lung pieces increased with time reaching a maximum value (0.5-0.9) by 1 h. Time constants (to) of cuff growth were similar to those (28 min) of the interstitial pressure (Pi) response measured by micropuncture at the lung hilum. Pi response was slower with saline (to = 84 min) than with albumin. Compared to saline, positively charged protamine sulphate increased the Pi response (to = 44 min). Time constants for cuff growth and Pi response were smaller at 15 cmH2O than at 5 cmH2O inflation pressure (30 vs. 60-120 min). Electrical analog models indicated a doubling of interstitial resistance with a four-to eight-fold decrease in interstitial specific compliance at the higher inflation pressure, the latter attributed to nonlinear elastic behavior of lung parenchyma.

Albumins↗
PubMed1996

Probabilities and lifetime durations of short-stay hospital and nursing home use in the United States, 1985.

OBJECTIVES: The authors present a four-state increment-decrement life table model from which estimates of the risk and duration of nursing home and short-term hospital stays in the United States are derived. METHODS: Survival analysis was used to generate various transition probabilities while controlling for population heterogeneity. In addition, a newly developed algorithm was applied to construct the multistate life table specifically for health-care use. RESULTS: The results reveal that in 1985, a US civilian is expected to spend 72.35 years in the community, 59.5 days in short-stay hospitals, and 2.28 years in nursing homes throughout his or her lifetime. CONCLUSIONS: The single-year risk of nursing home and short-stay hospital use is shown to be an increasing function of age, especially for the older adults.

Adolescent↗
PubMed1996

Quantitative analysis of peptides from myelin basic protein binding to the MHC class II protein, I-Au, which confers susceptibility to experimental allergic encephalomyelitis.

BACKGROUND: An important issue in autoimmune diseases mediated by T cells, such as experimental allergic encephalomyelitis (EAE), is the affinity of the disease-inducing determinants for MHC class II proteins. Tolerance, either due to clonal deletion or anergy induction, is thought to require high-affinity interactions between peptides and MHC molecules. Low-affinity binding is compatible with the hypothesis that breaking tolerance to self proteins does not have to occur for onset of disease. In contrast, a high-affinity interaction implies that an event leading to a breakdown of tolerance is central to the autoimmune process. MATERIALS AND METHODS: Detergent-solubilized and affinity-purified I-Au was incubated with varying concentrations of a set of peptides from myelin basic protein and a biotinylated peptide agonist. The specific complexes were separated from excess peptide by capture on antibody-coated plates, and the affinity of the peptides was measured by adding europium-labeled streptavidin and measuring the resultant fluorescence. RESULTS: The immunodominant and encephalitogenic determinant, Ac 1-11, was shown to bind to I-Au relatively poorly (IC50 = 100 microM), demonstrating that in this protein, immunodominance did not correlate with high-affinity binding. In contrast with the natural sequence, the ability of shorter analogs to induce EAE did correlate with their apparent affinity. CONCLUSIONS: The dominance of the natural determinant does not arise from a high-affinity interaction with the MHC class II molecule. This suggests that other mechanisms are operative and that the specific T cell for this peptide/MHC ligand is of high affinity.

Amino Acid Sequence↗
PubMed1996

Endoscopic ultrasonography assessment in preoperative staging for carcinoma of ampulla of Vater and extrahepatic bile duct.

OBJECTIVE: To evaluate preoperatively the extent of primary tumor, involvement of regional lymph node, and distant metastasis of ampullary carcinoma and extra hepatic bile duct carcinoma. METHODS: 28 patients with ampullary carcinoma and the 18 patients with extrahepatic bile duct carcinoma were subjected to endoscopic ultrasonography (EUS). The results were compared with those of surgical explorations and pathological findings of the resected specimens for evaluating the accuracy of preoperative staging of EUS. 46 patients underwent surgical explorations. Radical resection with detailed pathological study was done for 22 patients with resectable ampullary carcinoma and 18 patients with extrahepatic bile duct carcinoma. Carcinomas of ampulla of Vater and extrahepatic bile duct were staged according to the tumor, nodes, metastasis (TNM) classification. RESULTS: The accurate rate of EUS in assessing the extent of cancer invasion was 81.8% for ampullary carcinoma, and 72.2% for extrahepatic bile duct carcinoma. The accuracy of EUS in predicting regional lymph node metastasis was 59% for ampullary carcinoma, and 61.1% for extrahepatic bile duct carcinoma. Invasion of portal vein was correctly predicted by EUS in 2 of 3 patients, but the 3 cases of liver metastasis were not detected by EUS. CONCLUSIONS: EUS is an effective method for the evaluation of the extent of invasion of ampullary carcinoma and extrahepatic bile duct carcinoma as well as the involvement of regional lymph node before operation. Because of its limited penetration depth, however, EUS is inadequate in the assessment of liver metastasis.

Adolescent↗
PubMed1996

[Analysis of 106,272 cases of postterm pregnancy in China].

106272 cases of postterm pregnancy in 945 hospitals in China during the period from Oct. 1986 to Sept. 1987 were surveyed, the overall incidence rate was 85.48/1000. Provincially, the highest two rates were 127.36/1000 and 120.92/1000 in Jilin and Shandong provinces respectively, and the lowest two rates 53.98/1000 and 61.38/1000 in Xizang and Qinghai provinces respectively. The perinatal mortality was 27.90/1000 (corrected 12.49/1000). The incidence of macrosomia (89.50/1000) in postterm pregnancy was twice as much as that in term delivery. Postterm pregnancy was more frequent in pregnant women of 20-34 years old,and of 42 weeks' gestation. The incidence malformations in postterm pregnancy was 154.13 per ten thousand, in which the frequency of malformations associated with low birth weight was three times that associated with macrosomia.

Adult↗
PubMed1996

[Effects of high dose pulse oral calcitriol on secondary hyperparathyroidism in patients with end-stage renal disease].

To evaluate the therapeutic effects of high dose pulse oral calcitrol, 3.5 micrograms calcitrol three times a week and calcium carbonate were administered to 13 patients with end-stage renal disease on chronic hemodialysis with hyperparathyroidism refractory to conventional calcitrol therapy. Serum parathyroid hormone and osteocalcin were detected by radioimmunoassay. Serum parathyroid hormone level of the patients decreased from 1111 +/- 344 ng/L to 492 +/- 218 ng/L by 57.5 +/- 11.5 percent (P < 0.01) in 6 months after the beginning of treatment. Both serum alkaline phosphatase and osteocalcin levels declined markedly, and correlated positively with that of parathyroid hormone. Plasma calcium concentration was markedly elevated, but no obvious increase of plasma phosphate was found. High dose pulse oral calcitrol was effective on secondary hyperparathyroidism. During the course of treatment timely and individual adjustment of calcitrol dose and dialysate calcium concentration is essential.

Administration, Oral↗
PubMed1996

[Comparative analysis of clinical features of acute myocardial infarction in diabetic and non-diabetic patients].

We conducted match-control study to make a comparison between 20 diabetic and 20 non-diabetic patients in clinical features of acute myocardial infarction (AMI). There were 16 males and 4 females in each group. The mean age of diabetic group (DM) was 61.95 +/- 9.83 years, and that of non-diabetic group (NDM) was 61.45 +/- 9.38 years. We found the morbidity of silent myocardial infarction (MI) being 45% (DM) versus 10% (NDM); acute pulmonary edema being 40% (DM) versus 10% (NDM); cardiac shock, 35% (DM) versus 0% (NDM); arrhythmia, 70% (DM) versus 30% (NDM); the complication of cerebral infarction being 20% (DM) versus 0% (NDM); and complication of infection, 30% (DM) versus 10% (NDM). These revealed that DM had higher morbidity of silent MI and complications of AMI than NDM. Three diabetic patients had MI in two sites while one diabetic patient had myocardial remfarction, which showed DM had more serious damage in coronary artery than NDM. The mortality rate was 45% in DM and 15% in NDM. Multiple-organ functional failure was the main cause of death in DM.

Adult↗
PubMed1996

On the definition and the construction of pockets in macromolecules.

The shape of a protein is important for its functions. This includes the location and size of identifiable regions in its complement space. We formally define pockets as regions in the complement with limited accessibility from the outside. Pockets can be efficiently constructed by an algorithm based on alpha complexes. The algorithm is implemented and applied to proteins with known three-dimensional conformations.

Algorithms↗
PubMed1996

[Unroofed coronary sinus syndrome].

Unroofed coronary sinus syndrome or coronary sinus septal defect is a rare congenital cardiac anomaly. We performed corrective operations in 9 patients with such condition. Of them, seven patients had the completely unroofed coronary sinus and persistent left superior vena cava (PLSVC) directly draining into the left atrium (LA). One patient had PLSVC and the partially unroofed terminal portion of the coronary sinus (CS), or sinus ostium open into LA. Another patient had total anomalous pulmonary vein connection and the partially unroofed mid-portion of CS without PLSVC. The operative methods of the unroofed coronary sinus included: ligating PLSVC and repairing ostium primum or secundum atrial septal defects in 4 cases; creating an intra-atrial tunnel from PLSVC to the right atrium (RA) and repairing the atrial septal defect in 2 cases; reconstructing the intra-atrial septal with a patch as a baffle to guide PLSVC or sinus ostium respectively towards RA in 2 cases; enlarging the defect on the coronary sinus roof and repairing the atrial septal defect of the coronary sinus type in one case. No patient died in this group. Because unroofed coronary sinus syndrome has atypical clinical manifestation and usually complicates varied congenital anomalies, its preoperative diagnosis is very difficult in some times and may draw the reliable support from echocardiography and catheterization. The operative program and method must depend not only upon its type but also upon PLSVC presence of absence, and communication between PLSVC and RSVC.

Adolescent↗